Apparatus and method for tying coils

ABSTRACT

Apparatus and method for concurrently tying cord about two sets of end turn portions of coils projecting beyond each side surface of a magnetic core. The core having coils is supported in a holder assembly and periodically indexed through an angular path of travel by an assembly having adjustable arms. Each set of end turn portions is tied with cord in a stitch pattern having double loops in each stitch interval by a tying unit having a cord feeder member, mounted for combined longitudinally swinging and turning motion, which passes over the associated set of end turn portions and cooperates with an elongated hook member, mounted for combined rectilinear and oscillatory motion. One tying unit is carried for preselected movement by a movable platform, and a core-surface and tying unit position-sensing and controlling unit automatically determines the relative positions of the one tying unit with respect to an adjacent region of an associated core surface. Thus, desirable stitch patterns are simultaneously, quickly, and efficiently provided for the two sets of end turn portions. Also, dimensional variations in cores of a given size as well as different sized and types of cores are compensated for in an effective and economical manner.

[ 51 May 2, 1972 Primary ExaminerThomas H. Eager [57] ABSTRACT Apparatus and method for concurrently tying cord about two sets of end turn portions of coils projecting beyond each side surface of a magnetic core. The core having coils is supported in a holder assembly and periodically indexed through an angular path of travel by an assembly having adjustable arms. Each set of end turn portions is tied with cord in a stitch pattern having double loops in each stitch interval by a tying unit having a cord feeder member, mounted for combined longitudinally swinging and turning motion, which passes over the associated set of end turn portions and cooperates with an elongated hook member, mounted for combined rectilinear and oscillatory motion. One tying unit is carried for preselected movement by a movable platform, and a core-surface and tying unit position-sensing and controlling unit automatically determines the relative positions of the one tying unit with respect to an adjacent region of an associated core surface. Thus, desirable stitch patterns are simultaneousl quickly, and efficiently provided for the two sets of end turn portions. Also, dimensional variations in cores of a given size as well as different sized and types of cores are compensated for in an effective and economical manner.

25 Claims, 32 Drawing Figures both Apr. 2, 1969, aban- ....29/606, 29/203 ....H0lf4l/02 TYING COILS Inventors: Roy E. Gawthrop; Lowell M. Mason of Fort Wayne, Ind.

Assignee: General Electrlc Company Filed: Feb. 9, 1971 Appl. No.: 114,085

Related US. Application Data Continuation of Ser. No. 812,631 doned.

lnt. Field oi'Search........... ...29/606 References Cited UNITED STATES PATENTS Dixon Prazak... Haas....................... Ammann Harris........

United States Patent Gawthrop et al.

[54] APPARATUS AND METHOD FOR .4 latw l Fa H a. I i

PATENTEDMAY 2 I972 D 3, 659 337 SHEET 05 0F 11 1r? verz tors: Fay E Gawt/vrop, I 76 Lowe/l /7. Mason,

I BY WM 21. flLta/wcy.

PATENTEDMM 2 m2 3 659 337 us i BY 2?. 5 4

a Attorney.

IPATENZTEDMAY 2 m2 sum 10 [1F 11 [/7 van tars:

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5/ well M Mason,

fitter/ray 1 APPARATUS AND METHOD FOR TYING-COILS This application is a continuation of application, Ser. No. 8 12,63 1 ,filed Apr. 2, 1969, now abandoned.

BACKGROUND OF THE INVENTION The present invention relates to apparatus and a method of tying or lacing coils'in electromagnetic devices, and more particularly toapparatus and a method for controlling the relative positions of a dynamo-electric machine core and certain tyingcomponents during the binding of coil end turns projecting beyond the side faces of the core with appropriate cord or the like.

In the manufacture of certain electromagnetic devices, for example, certain dynamoelectric machine stators, it is desirable to bind the coil end turn portions adjacent each side face or surface of the laminated magnetic core carrying the coils (e.g., FIG. l in US. Pat. No. 3,299,304 ofB. B. Hull issued Jan. 17, 1967). In tying the coil end turn portions one of the tying components, usually an elongated member, is

reciprocated with rectilinear motion between adjacent coil sides next to the associated side surface of the outermost lamination as the member cooperates with. another member which swings over the end turns during a 360 indexed cycle of the stator. By virtue of undulations in the side surface, dimenunit automatically determines the relative positions of the-one tying unit with respect to an adjacent region of an associated core surface. This position-sensing and controlling-unit, in response to its sensor component, controls the position of the platform and hence the tying unit components it carries.

Thus, desirable stitch patterns may be simultaneously, quickly, and efficiently provided for the two sets of end turn portions. Also, dimensional variations in cores of a given size as well as different sized and types of cores are compensated for in an effective and economical manner which overcomes the difficulties mentioned heretofore. g

BRIEF DESCRIPTION OF THE DRAWINGS portion of the specification. Our invention, itself, however,

sional variations in stack heightsor axial lengths of cores of given size, and the limited space available for movement of the elongated member between next adjacent coil sides in the vicinity of the sidesurfaces, accuracy of the elongated members' position relative'to the associated side surface and adjacent coil sides is difficult to attain with any degree of regularity; Without such accuracy, there is a practical limitation on the speeds with which the member, and related tying components can move in continuous operation. Also, there is a tendency for the elongated member to strike part of the core from time to time, causing damage to the core and tying components. Further, such accuracy is especially difficult to attain when attempting to bind both sets of end turn portions concurrently.

SUMMARY OF THE INVENTION It is therefore an object of the invention to provide improved apparatus and method for tying coils in electromagnetic devices.

It is a further'object of the invention to provide improved apparatus and method for controlling with economy and efficiency the relative positions of a dynamoelectric machine core and certain tying components during binding of coil end turn portions for coilscarried by the core.

It is yet another object of the invention to overcome the diffic ulties and provide'the desirable features mentioned above.

In carrying out the object in one form, I provide an improved apparatus and method for concurrently tying cord about two sets of end turn portions of coils respectively projecting beyond each side surface of a magnetic core, for instance, a stator core in the illustrated exemplification. The core having coils is supported in a holder assembly and periodically indexed through an angular path of travel by an assembly having adjustable arms to permit variations in the angular extent of index. Eachset of end turn portions is tied with cord in a stitch pattern which, if desired, has double loops in each stitch interval.-Each tying unit associated with the set has a cord feeder member, mounted for combined longitudinally swinging and turning motion, which passes over the associated set of end turn portions and cooperating with an elongatedhook member, mounted for combined rectilinear and oscillatory motion.

The relative position-of the elongated member in one tying unit (the lower unit as shown) with respect to one side surface is regulated by the holder assembly. The other tying unit (the upper unit as illustrated) is carried for preselected movement towardand away'from'theone'tying unit by a platform, and a core-surface andtying unit'positionsensing and controllingboth as to its organization and method of operation, together with further advantages thereof, may best be understood by reference to the following description taken in connection with the accompanying drawings.

In the drawings: I 7

FIG. 1 is a view in'perspective of apparatus for tying coils incorporating one preferred embodiment of the present invention which is capable of practicing the novel method,

FIG. 2A is a side elevational view, partically broken away to shown detail, of the apparatus of FIG. 1; I I

FIG. 2B is a schematic presentation of tying related components of the apparatus of FIG. 1 including components for controlling the relative positions of the core withrespect to certain of the components; 7

FIG. 2C is an enlarged cross-sectional view of a part of the linkage shown in FIGS. 2A andZB for transmitting oscillatory motion to the'elongated hook member and turning motion to the cord feeder member of the adjustable upper tying unit;

FIG. 2D is an enlarged cross-sectional view of a part of the linkage shown in FIGS. 2A and 2B for transmitting longitudinally swinging motion simultaneously to the cord feeder members of both the adjustable upper and the lower tying units, the view also showing one way in which movement may be imparted to the upper tying unit relative to the lower unit;

FIG. 212 is a view in perspective, partially in schematic form, showing details in addition to the previous figures of the linkage for transmitting the desired motion to the cored feeder member of the upper tying member;

' FIG. 3 is a partial plan view, partly broken away, of the apparatus seen in FIG. 1, showing the automatic, axially adjustable upper coil-tying unit and core surface-tying unit position sensing and controlling unitas seen in the drawings; I

FIG. 4'is a plan view of the stationary lower coil-tying unit supporting frame;

FIG. 5 is an enlarged fragmentary view of a portion of the lower coil-tying unit and supporting frame;

FIG. 6 is a partially schematic view of the holder indexing assembly of the illustrated apparatus, the view showing the components indexing the holder assembly a preselected angle;

FIG.-7 is a view similar to that of FIG. 6 showing the components after the holder assembly has been indexed through the desired angle;

FIG. 8 is a cross-sectional view of a portion of the holder indexing assembly of FIGS. 6 and 7;

FIG. 9 is'a view in perspective of a part of the preferred dorm of the apparatus, showing the coil end turn portions being tied in accordance with one form of the inventive process;

FIG. 10A is a schematic diagram of the principle parts of T FIG. 11 is a plan view, partially schematic, of apparatus components imparting oscillatory motion to the stroke or path of travel of the elongated hook members of the tying components;

FIG. 12 is a schematic cam development diagram for the oscillatory motion controlling cam of theelongated hook memberofFIG. 11;

FIG. 13 is a plan view, partially schematic, of apparatus components imparting rectilinear motion to the stroke of the elongated hook members of the tying components;

FIG. 14 is a schematic cam development diagram for the rectilinear motion controlling cam of the elongated hook member ofFIG. 13;

FIG. 15 is a plan view, partially schematic, of apparatus components imparting longitudinally swinging motion to the stroke of the cord feeder members of the tying components;

FIG. 16 is a schematic cam development diagram for the longitudinally swinging motion-controlling cam of the cord feeder members of FIG. 15;

FIG. 17 is a plan view, partially schematic, of apparatus components imparting turning motion to the stroke of the cord feeder member;

FIG. 18 is a schematic cam development diagram for the turning motion-controlling cam of the cord feeder member of FIG. 17;

FIG. 19 is a diagrammatic illustration of certain tying relationships of the feeder and hook members in producing a stitch pattern having double loops in each stitch interval;

FIGS. 20A, B, C, D, E, and A are enlarged, partial perspective illustrations revealing the relative positions of the position sensor, cord feeder and elongated hook members at the cam positions A-E and A; cam angles 0, 96, 156, 216, 316 and against 0 respectively; shown in FIGS. 12, 14, 16 and 18; and

FIG. 21 is a view in perspective of the highly desirable kind of interlocked double looped stitch pattern which is possible to attain by use of the preferred form of the illustrated apparatus.

DESCRIPTION OF THE PREFERRED'EMBODIMENT Turning now to the drawings in more detail, in order to disclose the principles of our invention, improved apparatus incorporating the preferred form of the invention, capable of practicing one form of the inventive method, is illustrated in connection with tying or binding cord 21, 22 respectively about two sets of coil end turn portions 23, 24. These portions project beyond associated side faces or surfaces 25, 26 of a slotted magnetic core 27, a laminated stator core having a central bore 28 in the illustrated exemplification which has axial slots carrying side turn portions of two distributed wound phase windings conventionally displaced in phase from one another and insulated from the core by slot liners 29.

The preferred form of the coil end turnrlacing or tying apparatus, generally denoted by numeral 30, broadly includes an article or core holder assembly 31 mounted to a standard supporting frame 32, having a lower pedestal 35, a lower coil end turn-tying unit 33 (as viewed in the drawings) attached to the frame in a predetermined position with respect to assembly 31, an upper coil end turn-tying unit 34 adjustably carried for selected movement toward and away from lower unit 33, a core surface-tying unit position-sensing and controlling unit 36, and an indexing assembly 37 operatively connected to the core holder assembly. The apparatus also includes suitable power input devices, motion-controlling and driving mechanisms and linkages and other operating components to be more fully considered hereinafter.

With regard to core holder assembly 31, it has a rotatable, flanged mandrel 41 (FIG. 2A, B) which is adapted to fit within the stator bore 28 for supporting core 27 and transporting the coil end turn portions through angular paths of travel. The core may be located in the proper orientation on the mandrel relative to unit 33 in any convenient fashion; e.g., by a lower flange or shoulder 42, adapted to engage end surface near the bore to position that surface at a fixed location with respect to unit 33, and a number of axial keys 43 which fit into slot entrances at the stator bore. The mandrel has a lower extension 44 detachably connected by coupling 46 to a drive shaft 47 which in turn is periodically operated by indexing assembly 37. This arrangement allows the holder assembly to be easily removed and changed to another size for supporting different types and sizes of magnetic cores.

COIL END TURN TYING UNITS Considering lower coil end tum-tying unit 33, it has a generally L-shaped multi-piece cord feeder member 51 mounted to a stationary generally horizontal platform portion 39 of frame 32 for longitudinally swinging and oscillatory motions. More specifically, the trailing end 52 of section 59 of the member is formed with a rectangular cross-sectional configuration which projects through a bearing 53, having a suitably configured opening and carried by upright wall extension 54 of frame 32. The opening is dimensioned to permit longitudinal movement of member 51 through the bearing when the tubular-leading end section 56 of member 51 is swung over end turns 23, selectively between a retracted position, outside the core, and an extended position within bore 27 of the core (see FIG. 16). However, the size of the opening is such that end 52 is forced to turn in response to the angular position of the bearing. To provide the swinging motion (a combined vertical and horizontal movement) of member 51, a crank lever 57 is supported by bearing 58 (FIG. 4) mounted in frame 32 and has a pivoted arm attached to section 59, which in turn is adjustably interconnected with section 56 of member 51 by a pair of spaced apart split mounting blocks 61, 62. This latter construction allows the swinging motion of member 51 to be adjusted as desired to compensate for cores and end turns of different sizes merely by changing the relative positions of crank lever 57, and sections 59, 56, of member 51.

As best seen in FIG. 2A, B, tying or cord feeder member 51 feeds cord 21 from a cord supply spool 63 removably disposed in spool housing 64 which in turn is suitably attached to wall extension 54. The cord runs from the spool, through a standard cord-tensioning device 66 connected to housing 64, and through tubular-leading end section 56 of member 51 to a conventional cord cutting-clamping assembly 67. An upright bracket structure 68 has a leg extension 69 bolted to frame 32 to support assembly 67 in the proper spaced relation aside assembly 31 (FIGS. 1, 2A, and 9).

In the illustrated exemplification the component of unit 33 which cooperates with member 51 during the tying of end turn portions 23 is a multi-piece elongated tying or hook member 71 having its leading end section 72 formed with a hook and is removably attached by nut 73 to the remaining sections of member 71 Member 71 is supported by frame 32 for combined rectilinear and oscillatory motion by a bearing boss 76, integrally formed on the frame adjacent leading end section 72, and by the wall of an opening 77 adjacent trailing end section 78, which is formed with a rectangular cross-section. Boss 76 and opening 77 are each dimensioned to permit the desired sliding and turning movement as well as the proper support.

In regard to upper tying unit 34, it includes the same type of multi-piece cord feeder and elongated hook members and supporting structure as the lower unit except as mirror images thereof, best seen in FIGS. 2A, B, C, D, and E. Thus, these components are identified by similar numbers with primes and will not be further described in detail. These members are, however, supported by various walls of a cast carriage in the form of a platform 80, which is adjustably carried above portion 39 of frame 32 (as viewed in the drawings) such that it is capable of vertical movement with respect to holder assembly 31. The manner of achieving this support and movement will be considered after reviewing the illustrated arrangement for imparting the desired tying motions to members 51, 51, 71 and 71 of units 33 and 34.

MOTION-CONTROLLING MECHANISMS More specifically, a motion-controlling complementary cam system (see FIGS. 2A-E inclusive) is disposed vertically within a lower housing 81 of frame 32 which is beneath horizontal portion 39 and accessible through plate 85. The system has a central cam control shaft 82, supported for revolving movement by bearings 83, 84, which mounts four complementary cam pairs 86, 87, 88, and 89 which control, through suitable linkages, the desired motions imparted simultaneously to units 33, 34. In particular, supported for oscillatory movement in the housingin response to cam positions are four drive shafts 92, 93, 94, 95 in suitable ball-bearing 91 mounted in frame 32, the shafts respectively carrying double aimed cam followers 96, 97, 98, and 99. Rectilinear motion is imparted to members 71, 71' from cam pair 86, through follower 96, drive shaft 92, dovetail type sliding bearings 101 and 101' on members 71, 71' and arms 102, 102, arm 102 being attached for sliding vertical motion to an upper splined portion 924 of drive shaft 92. Turning or oscillatory motion is imparted concurrently in mirror image to members 71, 71' from cam pair 88, through follower 98, shaft 94, segmented spur gear 104 connected to shaft 94, spur gear 106, shaft 107, spur gears 108, 108 (the upper gear slidably attached to shaft portion 107a), rectilinearly movable racks 109, 109 meshing with gears 111, 111 and carried by wall extension 54 of stationary portion 39 and wall extension 54 of adjustable platform 80. These latter gears are in turn respectively attached to trailing ends 77, 77 ofmembers 71, 71.

With respect to feeder members 51, 51, concurrent turning motion is imparted thereto from control cam 87, through follower 97, shaft 93, and crank levers 113, 113', with lever 113' being slidably received on splined shaft section 93a. These latter levers are in effect connected to turn members 51, 51 in unison respectively through bearings 53, 53'. As to the longitudinally swinging motion, this is furnished concurrently to members 51, 51' by the crank levers 57, 57 controlled by cam pair 89 through cooperating follower 99, shaft 95, and the remaining linkage including segmented'spur gear 116, spur gear 117, post 118, and meshing helical gears 119, 121, and 119, 121 which are attached to turn respectively lever shafts 122, 122. To permit vertical movement of gear 119', it rides on a splined end 118a ofpost 118.

Any suitable source of power may be employed to turn cam control shaft for turning the cams through 360 with the desired speed, for instance 60 rpm. In the illustrated exemplification an electric motor 123 has its output shaft attached to a standard clutch-brake assembly 124 which has the driven side provided with a worm gear 126 in meshing relation to a worm gear 127secured to shaft 82 for this purpose.

POSITION-SENSING AND CONTROLLING UNIT 36 By one feature of the present invention, the position-sensing and controlling unit 36 is furnished for automatically locating the path of travel of end 72' of member 71' (and associated components of unit 34) in closely spaced relation to an adjacent region of surface 26 regardless of the actual dimension between that surface and the components in unit 33. In the illustrated exemplification, a positionsensing element 131 has a shoe 132 detachably attached to the forward end of an arm of the element. This shoe is adjustable in a radial direction so that it will engage a region of core 27, regardless of size, in the vicinity of, e.g., adjacent the path of travel for section 72', preferably within five-eighth of one inch. Thus, it will be responsive to the height of that region relative to member 71'. Element 131 has a second, transverse arm 134 operatively connected on one end to air cylinder 136 and at an intermediate location through link 137 to a valve spool 138 of servo-hydraulic valve 139, such as a Vickers valve No. SV loA-l l-l I. This latter valve is secured to move with platform 80 by brackets I41 and plate 142. The actual vertical movement of the platform, including the components carried by it, is effected by a hydraulic cylinder 143 which has a piston rod 144 connected at one end to the platform and is actuated by valve 139. An L-shaped bar 146 is mounted at its lower end by split blocks 147 to frame 32 while its upper free end 148 is disposed in the path of movement of element 131 to provide an upper limit for the position of element 131 when unit 34 is located in its upper raised attitude out of operative relation with the core 27.

It will be appreciated from the drawings and in particular from FIGS. 3 and 4, that platform is guided for regulated vertical travel on splined shaft portions 92a, 93a, 107a, and 118a (with suitable collars designated by b") and an additional guided support is afforded by a guide post 149 disposed next to members 51', 71' which are carried during the vertical travel to the desired positions by the platform. Moreover, linkages including arm 102, gears 108', 119, 121', and crank lever 113' which may be disposed beneath platform 80 and attached thereto by suitable L-shaped brackets, clamping structures suchas those generally indicated at in FIG. 2D, or the like are all arranged to move in unison with the platform as well as gear 111' and rack 109 carried in a groove 125a (FIG. 2C) by upright wall extension 54' of the platform. It should be noted at this time that the upper cord cutting-clamping assembly 67"is also mounted to platform 80 so that it, too, will move in unison with unit 34.

More specifically, with reference to FIGS. 1, 2A.and especially FIGS. 9 and 20A, assembly 67 like its lower counterpart 67, includes a slotted sleeve 151 having a forward cutting edge 151a normally maintained out of engagement with the cord, and a cord-clamping edge which cooperates with a central rod like element 152 projecting through the sleeve to a forward cord-receiving transverse slot 153. A spring and pinin-slot arrangement 154 biases the sleeve and element in a normally clamping engagement, best seen in FIG. 20A. The element projects through a vertical groove formed in plate 68, the groove being denoted 156 for the lower element and at 157 for the upper element. The rear part of the element contains a nut 158 adapted to engage the plate when the two'elements are'moved in unison toward an initial cord pick-up and cutting position when the tying members are disposed in the relative locations revealed in FIG. 20A.

Assemblies 67 and 67' are united for joint movement by a lower split block 161, attached to the piston rod of an actuating air cylinder 162 and to the lower assembly. The block is secured to the bottom of a vertical guide post 163 along which a second split block 164 is adapted to slide in response to the exact vertical instantaneous .location of platform 80 (and hence upper tying unit 34) which in turn is determined and controlled by unit 36. This second split block carries assembly 67 and is connected to platform 80 through bracket 166 (FIG. 1) transverse bar 167 passing through an extension of bracket 166, and spaced support walls 168, 169 attached atone end of the platform. It should be noted that transverse travel of assemblies 67,67 between the retracted positions of FIG. 1 and the fully extended positions, where slot 153 is fully open to accept the cord extending between the feeder members and the core, is guided by the bar 167 at one location. A transverse lower tack 170, which is connected to frame 32, is employed to guide lower block 161 at a lower location to provide stability and accuracy in the transverse joint travel for assemblies 67, 67'.

INDEX ASSEMBLY 37 With respect to the illustrated arrangement for indexing the holder assembly 31 with intermittent angular motion for moving or transporting the core having coils through the stitching cycle, reference should be made to FIGS. 2A, 2B, 6, 7, and 8. Assembly 31, disposed within housing 81, has a disc element 171 connected directly to rotate with holder drive shaft 47. The disc is operatively connected to control shaft 82 so that it is intennittently rotated by three commercially available cooperating disc brake calipers 172, 173, and 174 of standard construction (e.g., a Horton disc brake Model D, B. No. 8350) and two elongated arms 176, 177. Each caliper conventionally includes two friction shoes 178, 179 adapted to engage each side of the disc as seen in FIG. 8. Arm 176 carries two of the calipers while the other caliper is secured to frame 32. Arms 176, 17 7 are adjustably connected at one end by a pair of free floating cylinders 181, 182, with piston rod cylinder 181 having a pin 183 on its piston rod located in elongated slot 184 of arm 176 thereby pivotally connecting the two arms together. Bracket 185 fixedly secures the other piston rod to arm 176 between shaft 47 and slot 184. The end of arm 177, remote from arm 178, is eccentrically mounted to spur gear 186 which meshes with a spur gear 187 of a commercially available acceleration deceleration unit 188 for speed controlling reason e.g., Hilliard IDU-ADU unit, 115 v. 60 cycle). The input gear 189 of the unit meshes with a speed reducing spur gear 191 which is adapted to rotate with shaft 82 through sprockets 192, 193 and chain 194.

In operation, continuous rotation of gear 186 causes movement of arm 177 between the indexing position of FIG. 6 and the return, non-indexing position of FIG. 7. To effect an appropriate index through the desired angle, disc 171 is caused to rotate in the direction of the arrow (FIG. 6) by actuating calipers 173, 174'to close them into driving engagement with the disc while caliper 172 is open to permit the disc to pass freely through it. When the desired extent of angular displacement or index has occurred, calipers 173, 174 open and caliper 172 closes to prevent further rotation of the disc as arm 177 is being returned from the position shown in FIG. 7 to that in FIG. 6.

The desired total'angular travel of disc 1'71, and hence of unit 31 and the core held thereby, is controlled by the exact position of pin 183 in slot 184, FIG. 7 listing examples of various pin setting and index angles attained therewith. The different settings may be achieved by operation of cylinders 181, 182 to place pin 183 at the desired pivot location in slot 184.

OP ERATION OF APPARATUS 30 AND METHOD OF TYING In considering operation of the tying apparatus when concurrently binding cord or string around the two sets of coil end turn portions 23, 24 in the exemplification, FIGS. 10-21, inclusive, should be consulted and in particular FIGS. 10A, B, and C at-the outset. With specific reference to FIG. 10B, motor 123 and pump motor 201 for pump 202 in the illustrated example are connected in circuit through normally open relay switches 20421 and b and manually actuated disconnect switch 206 to a suitable power source, for instance, a 60 cycle, 440 volt A.C. source. A voltage step-down transformer 207, having a primary input winding connected to the power source in circuit with switch 206, has its secondary output winding in a lower voltage circuit, has manually operated pump start and stop switches 208, 209, with normally open switch relay 204a in parallel across start switch 208. A similar and parallel circuit branch is provided for the motor, including start and stop switches 212, 213, normally open relay switch 204d and normally open auxiliary relay-switch 204e. This latter switch may be used to deenergize motor 123 automatically should pump motor 201 be turned off.

With switches 206, 209, and 213 closed, manual actuation of switches 208, 212 to the closed position energizes the relay thereby closing switches 204a -e inclusive. This places pump motor 201 and motor 123 in effect in closed circuit with the source of power. However, clutch-brakeassembly 124 is in a disengaged-operating condition and no power input is being applied through gears 126, 127 to turn control shaft 82. Also at this time, platform 80 is in its raised attitude and tying units 33, 34 and assemblies 67, 67 are in their retracted positions shown in FIG. 1 preparatory to initiation of the stitching cycle which are the same positions they assume upon completion of the cycle. 1

Depression of a suitable lever, e.g., foot pedal 216 (FIG. 10B) causes linkage 217 and also causes the release of pivot yoke section 218 to air switch 237. This switch acts to bleed fluid, such as air, from air cylinder 136 (see FIG. 10), permitting the spool of valve 139 to shift, which in turn effects oil to be pumped to the rod side of hydraulic cylinder 143. Since the housing of cylinder 143 is attached to movable platform while piston rod 144 of the cylinder is fixedly fastened at 145 to stationary portion 39 of frame 32, the oil flow into cylinder 143 produces a lowering of the cylinder housing, platform 80 and all components (e.g., unit 34, assembly 67') carried by it. Upon shoe 132 of element 131 making contact with the upper surface 26 of stator 27, the spool of valve 139 is centered by element 131 and oil flow to the rod side of cylinder 143' is immediately terminated to prevent further downward travel of .the platform and components carried by it. Consequently, members 51, 71' and assembly 67' are all in the proper locations for the first stitch interval as determined by the region of core surface 26 adjacent the path of travel for elongated member 71'.

When the foot pedal is depressed, it actuates air switch 237 as described above and also starts the timer T, (FIG. 10A), the timer being set to time out after shoe 132 engages core surface 26. At this time, fluid such as air is released from cylinder 221 causing the spring 222 to expand and return the piston toward the right to move link 223. The yoke being connected with the piston through the link, is operated such that the clutch 124 becomes fully engaged and power is applied to rotate control shaft 82 at a predetermined speed; e.g., 60 rpm.

FIGS. 2A, B and 20A illustrate the apparatus components in their respective retracted positions ready to tie cord or string simultaneously about end turn portions 23, 24, with members 51, 51', 71, 71 being outside and free of stator core 27. As shaft 82 is rotated, cams 86-89 inclusive are rotated through the cam angles as the developments show in FIGS. 12, 14, 16, 18 to produce appropriate tying movements of members 71, 71', 51, 51f shown by FIGS. 11,13, 15,17, and 20A E, A to produce the highly desirable stitch pattern having the double looped stitch intervals clearly revealed in FIG. 21.

Considering the formation of one stitch interval, which is achieved each 360 rotation of shaft 82, it will be assumed that the end turns have been stitched to the point shown in FIG. 20A. At this time, index assembly 37, as revealed in FIG. 6, turns shaft 44, holder, assembly 31, core 27, and hence end turn portions 23, 24 are angularly displaced as shown by the arrow a stitch interval through part of an angular or arcuate path of travel. A previously formed loop 22a is in the hook of members 71, 71 which faces associated feeder tubes 56, 56' disposed toward each other.

Continued rotation of shaft 82 and the cams, through the appropriate linkage, causes elongated members 71, 71' to turn away from feeder members 56, 56' and to swing the feeder members upwardly to assume that shown in FIG. 208 which represents cam travel of 96. During this period, the second loop 22b is being formed outwardly of the end turn portions as members 71, 71' travel rectilinearly toward the bore, between adjacent coil sides and between end turn portions 23,24 and the associated core surfaces 25, 26. However, no oscillatory motion is yet imparted to members 71, 71 until the cam angle 132 when they begin to turn to place the hook in a position away from the core. Cord loops 22a stay around members 71, 71 outside the end turn portions, near the associated core surface.

Additional rotation of the cams effect travel of the members to their extended positions inside the confines of the end turn portions at the bore where, as illustrated in FIGS. 11-19 and 20C and D, elongated members 71, 71 turn away from their associated feeder members 51, 51' to form cord loop 22a for the next stitch interval. During thistravel a single strand of cord 22c is provided over the end turn portions. The hooks on members 71, 71' are oscillated down, away from the feeder members, and as the feeder and hook members are returned toward their retracted positions of FIG. 20A, single strand 224 is furnished over the end tum portions, and loop 22a is pulled back between the end turn portions and adjacent core surface as seen in FIG. 20E. The hook of each elongated member is oscillated back toward the location shown in FIGS. 20A, A in the manner revealed in FIGS. 11-13 inclusive. The motion for the feeder members is illustrated by FIGS. 15-19. With the components in the relative positions seen in FIG. A, the index assembly 37 once again transports the end tum portions a selected extend of angular displacement, and the double loop stitch interval of the tying cycle is sequentially repeated until the stitch pattern has been fully completed or finished.

By one aspect of the present invention, once the core is being indexed, shoe 32 of element 131 senses height irregularities in the next region of the upper side surface 26 adjacent the path of travel of the elongated member 71'. Arm 134 is caused to actuate valve 139 through link 137 in response to the location of this next region, oil flow being regulated to cylinder 143 in a direction to selectively raise or lower platform 80 and the components carried by it which are automatically and accurately conveyed to the desired relative positions to compensate for such dimensional irregularities. In this way, dimensional variations are efficiently taken into consideration and the tendency of the components of unit 34 are assembly 67 in striking the stator and potentially damaging it and tying components as well as interfering with the stitching cycle are greatly reduced, if not entirely eliminated.

Upon completion of the 360 stitching cycle for the stator (or shorter if desired), the apparatus stops indexing, and air is supplied into the piston side of cylinder 162 through standard flow control valves 226, 227 having free flow in one direction, controlled flow in the other direction. This in turn shifts cord cutting-clamping assemblies 67, 67' to their extended positions where they sever the cord adjacent the end turn portions and pick up cord next to the cord outlets in tubes 56, 56 in the manner already outlined. A valve switch-valve 228 is tripped when assemblies are fully extended and air flow is reversed to cylinder 162 for returning assemblies 67, 67 to their retracted positions. During such return, cord is pulled out of tubes 56, 56 as the components all assume the relative positions shown in FIGS. 1 and 20A. Thereafter the finished core may be removed from holder assembly 31 and replaced with a core having end turn portions to be bound.

It should be noted that when assemblies 67, 67' are in their extended positions, they actuate switch and valve arrangement 231 (FIG. 10A), sending a flow of air through standard guide exhaust and pilot valves 232, 233 to valve 234, causing an air flow to the piston side of cylinder 136. This produces outward movement of the piston rod and, by virtue of its connection to element 131, creates a false reading for arm 134, which shifts spool of valve 139. Valve 139 regulates flow to the piston side of hydraulic cylinder 143 to raise platform 80 and the components carried by it to the raised location (FIG. 1) out of the way of the stator. As element 13] touches adjustable stop 148, the spool in valve 139 is centered so that flow to hydraulic cylinder 143 is shut off and the platform and components associated with it are held in the raised position preparatory to initiation of a stitching cycle for the next core having coils. Operation of valve 234 also results in air flow through valve 236 to air cylinder 221. Spring 222 is thus compressed, extending rod 223 for moving the yoke so that the clutch is once again locked out of driving engagement until released during the next cycle in the way already explained.

It will be appreciated from the foregoing that an effective and efficient arrangement is provided which is capable of simultaneously tying two sets of end turn portions wherein the relative positions of the tying unit and other components with respect to the core are automatically and effectively con- I trolled. In addition variations in cores of a given size as well as different sizes and types of cores and windings are automatically taken into consideration with economy and efiiciency thereby overcoming the difiiculties set out above. The present invention is also capable of producing a stitch pattern including double looped stitch intervals if so desired, which is accomplished efficiently and quickly.

It should be apparent to those skilled in the art that while we have shown and described what at present is considered to be the preferred embodiments. of our invention in accordance with the Patent Statues, changes may be made in the structures disclosed without actually departing from the true spirit and scope of this invention, and'we therefore intend to cover in the following claims all such equivalent variations as fall within the invention.

What we claim as new and desire to secure by Letters Patent of the United States is:

1. Apparatus for concurrently tying cord about first and second end turn portions of coils projecting respectively beyond first and second side surfaces of a magnetic core carrying side turn portions of the coils comprising: holding means for supporting the core; indexing means for periodically transporting each of the coil end turn portions through an angular path of travel as the core is supported by the holding means; first means for tying the first coil end turn portions; second means, including an elongated member adapted to move between the second coil end turn portions and the second side surface of the core, for tying the second coil end turn portions as the first means ties the first end turn portions; means for adjustably mounting the second means relative to the first means; and means, including an element mounted adjacent the elongated member of the second means, for sensing and controlling the position of at least that elongatedmember with respect to a preselected region of the second side surface of the core to reduce the tendency of the elongated member to make impact with the core thereby becoming damaged as the first and second end tum portions are being tied.

2. The apparatus of claim 1 in which the means for adjustably mounting the second means relative to the first means includes a platform supporting the elongated member for reciprocating and oscillating motion; and the second means includes a cord feeding member, supported by the platform, for looping cord over the second end turn portions and into cooperating engagement with the elongated member in a repeated predetermined tying cycle to bind the second end turn portions.

3. The apparatus of claim 1 ,in which the holding means includes a shaft, and the indexing means comprises linkage connected to the shaft for angularly displacing the shaft through a part of the angular path and having an adjustable arm dimensioned to control the extent of the angular displacement.

4. The apparatus of claim 1 including first and second cordcutting and clamping means each mounted for movement between a retraced position where cord is held and an extended position where cord is picked up and cut respectively adjacent said first and second means for tying coil end turn portions, with said second cutting and clamping means being mounted to move toward and away from said first cutting and clamping means in unison with said second means for tying the second end turn portions as it moves toward and away from said first means for tying the first end portions.

5. The apparatus of claim 1 including means for controlling the movement of said first and second tying means for respectively tying first and second end turn portions to produce a stitch pattern having double looped stitch intervals for the cord being tied about the end turn portions.

6. The apparatus of claim 1 in which the first and second means for tying end turn portions each includes a cord feeding member mounted for longitudinally swinging and turning motion to loop cord over the associated end turn portions and into cooperative engagement with the elongated member, to find the end turn portions; means for imparting longitudinally swinging and turning motion to each of said cord feeding members; and means for imparting rectilinear and oscillatory motions to the elongated member.

7. The apparatus of claim 6 having a plurality of cam means on a control shaft for simultaneously controlling actuation of the latter two means recited in claim 6.

8. The apparatus of claim 7 in which the indexing means includes linkageconnecting the holding means in driven relation to the control shaft, said linkage having an adjustable arm dimensioned to control the, extent of angular path of travel of the first and second coil end turn portions.

9. Apparatus for tying cord about at least one end turn portion of coils projectingbeyond an associated side surface of a magnetic core carrying side turn portions of the coils comprising: holding means for supporting the core; indexing means for periodically transporting the at least one coil end turn portion through an angular path of travel as the core is supported by the holding means; tying means for binding with cord the at least one coil end turn portion, including an elongated member adapted to move between the at least one coil end turn portion and the associated side surface of the core; means for adjustably mounting the tying means relative to the associated side surface; and position-controlling means, including an element mounted adjacent the elongated member, for sensing and regulating the position of at least that elongated member with respect to a preselected region of the associated side surfaceof the coreto reduce the tendency of the elongated member to become damaged as the at least one end turn portion is being bound with cord.

10. The apparatus of claim 9 in which the tying means includes a cord feeder member for looping cord over the at least one end turn portion and into cooperating relation with the elongated member in a repeated predetermined tying cycle to bind the at least one end turn portion, and the means for adjustably mounting the tying means relative to the associated side surface includes a support having means mounting the elongated member for rectilinear and oscillatory motion and the cord feeder member for longitudinally swinging and tuming motions to effect the binding of the at least one end turn portion.

11. The apparatus of claim 9 in which the holding means includes a shaft, and the indexing means comprises linkage connected to the shaft for angularly displacing the shaft through a part of the angular path and having at least one adjustable arm dimensioned to control the extent of the angular displacement.

12. The apparatus of claim 9 including a cord cutting and clamping means carried by a support adjacent the tying means for travel between a retracted position where cord is held and an extended position where cord is picked up and cut, said tying means and position-controlling means each being attached to the support for travel therewith.

13. The apparatus of claim 9 in which the means for tying the end turn portion includes a cord feeder member mounted for longitudinally swinging and turning motion to loop cord over the end turn portion and into cooperative relation with the elongated member to bind the end turn portion; motion imparting means for transmitting longitudinally swinging and turning motion to said cord feeder member; and motion imparting means for transmitting rectilinear and oscillatory motions to the elongated member.

14. The apparatus of claim 13 in which each motion imparting means includes cam means carried by a single control shaft for simultaneously controlling operation of the elongated and cord feeder members,

15. Apparatus for tying cord about at least one end tum portion of coils projecting beyond an associated side surface of a magnetic core carrying side turn portions of the coils comprising: holding means including a shaft for supporting the core; a control shaft; indexing means for intermittently driving them least one coil end turn portion through an angular path of travel as the core is supported by the holding means, said indexing means comprising linkage connecting the holding means in driven relation to the control shaft, said linkagehaving an adjustable arm dimensioned to control the extent of angular path of travel of the at least one end turn portion; tying means for binding with cord the at least one coil end turn portion, including an elongated member adapted to move between the at least one coil end turn portion and the associated side surface of the core, and a cord feeder member adapted to longitudinally swing over the at least one coil end turn in cooperation with the elongated member; and means for adjustably mounting the tying means relative to the as sociated side surface.

16. The apparatus of claim 15 including means for concurrently controlling the tying motion of the elongated member and the cord feeder member to produce a stitch pattern having double looped stitch intervals, with one loop being formed on one side of the at least one end turn portion and the second loop being formed on the other side of the one end turn portion.

17. Apparatus for tying cord about at least one end turn portion of coils projecting beyond an associated side of a magnetic core carrying side turn portions of the coils comprising: holding means for supporting the magnetic core having the coils; a first tying means for binding the at least one coil end turn portion with cord; indexing means for periodicallymoving the at least one coil end turn portion and first tying means relative to one another through an angular path; support means for adjustably mounting the first tying means with respect to the associated side of the magnetic cord; and position-controlling means for sensing a desired position of the support means and first tying means relative to the associated side of the magnetic core and for regulating movement of the support means and first tying means into the desired position relative to the associated side of the magnetic core.

18. The apparatus of claim 17 in which the support means for adjustably mounting the first tying means with respect to the associated side of the magnetic core mounts a cord-cuttin g I and clamping device in the vicinity of the tying means for travel between two positions respectively where the cord is held and where the cord is picked up and cut.

19. The apparatus of claim 17 in which the first tying means v includes an elongated member adapted to travel between the at least one coil end turn portion and an associated surface of the magnetic core, and the support means for adjustably mounting the first tying means with respect to the associated side of the magnetic core comprises an assembly supporting the elongated member for movement toward and away from the associated side of the magnetic core in a repeated predetermined tying cycle to bind the atleast one end turn portion with cord.

20. The apparatus of claim 19 in which the first means for tying the at least one end turn portion includes a cord feeder member attached to the support means for longitudinally swinging and turning motion to loop cord over the at least one end turn portion; motion imparting means for transmitting such motion to said cord feeder member; and motion imparting means for transmitting rectilinear and oscillatory motions to the elongated member.

21. A method of concurrently tying cord about end turn portions of coils projecting respectively beyond each side surface of a magnetic core carrying the coils comprising the steps of: disposing one of the side surfaces of the core in a predetermined position relative to an elongated tying member having a path of travel between the one side surface and the associated end turn portion of the coils; establishing the path of travel of another elongated tying member between another side surface of the magnetic core and the associated end turn portion of the coils by sensing the location of a preselected region of the other side surface and the path of travel of the another elongated tying member; and concurrently tying cord about the end turn portions as the elongated members move along their respective paths of travel between the respective end turn portions and the associated side surface of the magnetic core.

by sensing the location of another preselected region of the other side surface and the path of travel of the another elongated tying member.

23. The method of claim 22 in which the tying cord about the end turn portions includes the step of producing a stitch pattern having a plurality of double looped stitch intervals, by forming a first loop in the intervals on one side of the end turn portions, by forming a second loop in the interval on another side of the end turn portions, pulling the first loop beneath the end turn portions to the same side as the second loop, and passing it through the second loop.

24. A method of tying cord about at least one end turn portion of coils projecting beyond an associated side surface of a magnetic stator core carrying the coils comprising the steps of:

disposing the associated side surface of the stator core in a predetermined position relative to an elongated tying member having a path of travel between the at least one end turn portion and the associated. side surface; establishing a longitudinally swinging path of travel for a cord feeder member over the at least one end turn portion, sensing the location of a preselected region of the associated side surface adjacent the path of travel of the elongated tying member and controlling the paths of travel relative to the preselected region; and tying cord about the at least one end turn portion as the elongated member and the cord feeder member move along their respective paths of travel.

25. A method of tying cord about at least one end turn portion of coils projecting beyond an associated surface at a given side of a magnetic core carrying the coils comprising the steps of: disposing the associated surface of the magnetic core in a predetermined position relative to a first tying member having a path of travel between the at least one end tum portion and the associated surface; establishing a longitudinally swinging path of travel for a second tying member over the at least one end turn portion; sensing a preselected location of the given side adjacent the path of travel of the first tying member and controlling the paths of travel relative to the preselected location; and tying cord about the at least one end turn portion as the first and second tying members move along their respective paths of travel. 

1. Apparatus for concurrently tying cord about first and second end turn portions of coils projecting respectively beyond first and second side surfaces of a magnetic core carrying side turn portions of the coils comprising: holding means for supporting the core; indexing means for periodically transporting each of the coil end turn portions through an angular path of travel as the core is supported by the holding means; first means for tying the first coil end turn portions; second means, including an elongated member adapted to move between the second coil end turn portions and the second side surface of the core, for tying the second coil end turn portions as the first means ties the first end turn portions; means for adjustably mounting the second means relative to the first means; and means, including an element mounted adjacent the elongated member of the second means, for sensing and controlling the position of at least that elongated member with respect to a preselected region of the second side surface of the core to reduce the tendency of the elongated member to make impact with the core thereby becoming damaged as the first and second end turn portions are being tied.
 2. The apparatus of claim 1 in which the means for adjustably mounting the second means relative to the first means includes a platform supporting the elongated member for reciprocating and oscillating motion; and the second means includes a cord feeding member, supported by the platform, for looping cord over the second end turn portions and into cooperating engagement with the elongated member in a repeated predetermined tying cycle to bind the second end turn portions.
 3. The apparatus of claim 1 in which the holding means includes a shaft, and the indexing means comprises linkage connected to the shaft for angularly displacing the shaft through a part of the angular path and having an adjustable arm dimensioned to control the extent of the angular displacement.
 4. The apparatus of claim 1 including first and second cord-cutting and clamping means each mounted for movement between a retraced position where cord is held and an extended position where cord is picked up and cut respectively adjacent said first and second means for tying coil end turn portions, with said second cutting and clamping means being mounted to move toward and away from said first cutting and clamping means in unison with said second means for tying the second end turn portions as it moves toward and away from said first means for tying the first end portions.
 5. The apparatus of claim 1 including means for controlling the movement of said first and second tying means for respectively tying first and second end turn portions to produce a stitch pattern having double looped stitch intervals for the cord being tied about the end turn portions.
 6. The apparatus of claim 1 in which the first and second means for tying end turn portions each includes a cord feeding member mounted for longitudinally swinging and turning motion to loop cord over the associated end turn portions and into cooperative engagement with the elongated member, to find the end turn portions; means for imparting longitudinally swinging and turning motion to each of said cord feeding members; and means for imparting rectilinear and oscillatory motions to the elongated member.
 7. The apparatus of claim 6 having a plurality of cam means on a control shaft for simultaneously controlling actuation of the latter two means recited in claim
 6. 8. The apparatus of claim 7 in which the indexing means includes linkage connecting the holding means in driven relation to the control shaft, said linkage having an adjustable arm dimensioned to control the extent of angular path of travel of the first and second coil end turn portions.
 9. Apparatus for tying cord about at least one end turn portion of coils projecting beyond an associated side surface of a magnetic core carrying side turn portions of the coils comprising: holding means for supporting the core; indexing means for periodically transporting the at least one coil end turn portion through an angular path of travel as the core is supported by the holding means; tying means for binding with cord the at least one coil end turn portion, including an elongated member adapted to move between the at least one coil end turn portion and the associated side surface of the core; means for adjustably mounting the tying means relative to the associated side surface; and position-controlling means, including an element mounted adjacent the elongated member, for sensing and regulating the position of at least that elongated member with respect to a preselected region of the associated side surface of the core to reduce the tendency of the elongated member to become damaged as the at least one end turn portion is being bound with cord.
 10. The apparatus of claim 9 in which the tying means includes a cord feeder member for looping cord over the at least one end turn portion and into cooperating relation with the elongated member in a repeated predetermined tying cycle to bind the at least one end turn portion, and the means for adjustably mounting the tying means relative to the associated side surface includes a support having means mounting the elongated member for rectilinear and oscillatory motion and the cord feeder member for longitudinally swinging and turning motions to effect the binding of the at least one end turn portion.
 11. The apparatus of claim 9 in which the holding means includes a shaft, and the indexing means comprises linkage connected to the shaft for angularly displacing the shaft through a part of the angular path and having at least one adjustable arm dimensioned to control the extent of the angular displacement.
 12. The apparatus of claim 9 including a cord cutting and clamping means carried by a support adjacent the tying means for travel between a retracted position where cord is held and an extended position where cord is picked up and cut, said tying means and position-controlling means each being attached to the support for travel therewith.
 13. The apparatus of claim 9 in which the means for tying the end turn portion includes a cord feeder member mounted for longitudinally swinging and turning motion to loop cord over the end turn portion and into cooperative relation with the elongated member to bind the end turn portion; motion imparting means for transmitting longitudinally swinging and turning motion to said cord feeder member; and motion imparting means for transmitting rectilinear and oscillatory motions to the elongated member.
 14. The apparatus of claim 13 in which each motion imparting means includes cam means carried by a single control shaft for simultaneously controlling operation of the elongated and cord feeder members.
 15. Apparatus for tying cord about at least one end turn portion of coils projecting beyond an associated side surface of a magnetic core carrying side turn portions of the coils comprising: holding means including a shaft for supporting the core; a control shaft; indexing means for intermittently driving the at least one coil end turn portion through an angular path of travel as the core is supported by the holding means, said indexing means comprising linkage connecting the holding means in driven relation to the control shaft, said linkage having an adjustable arm dimensioned to control the extent of angular path of travel of the at least one end turn portion; tying means for binding with cord the at least one coil end turn portion, including an elongated member adapted to move between the at least one coil end turn portion and the associated side surface of the core, and a cord feeder member adapted to longitudinally swing over the at least one coil end turn in coOperation with the elongated member; and means for adjustably mounting the tying means relative to the associated side surface.
 16. The apparatus of claim 15 including means for concurrently controlling the tying motion of the elongated member and the cord feeder member to produce a stitch pattern having double looped stitch intervals, with one loop being formed on one side of the at least one end turn portion and the second loop being formed on the other side of the one end turn portion.
 17. Apparatus for tying cord about at least one end turn portion of coils projecting beyond an associated side of a magnetic core carrying side turn portions of the coils comprising: holding means for supporting the magnetic core having the coils; a first tying means for binding the at least one coil end turn portion with cord; indexing means for periodically moving the at least one coil end turn portion and first tying means relative to one another through an angular path; support means for adjustably mounting the first tying means with respect to the associated side of the magnetic cord; and position-controlling means for sensing a desired position of the support means and first tying means relative to the associated side of the magnetic core and for regulating movement of the support means and first tying means into the desired position relative to the associated side of the magnetic core.
 18. The apparatus of claim 17 in which the support means for adjustably mounting the first tying means with respect to the associated side of the magnetic core mounts a cord-cutting and clamping device in the vicinity of the tying means for travel between two positions respectively where the cord is held and where the cord is picked up and cut.
 19. The apparatus of claim 17 in which the first tying means includes an elongated member adapted to travel between the at least one coil end turn portion and an associated surface of the magnetic core, and the support means for adjustably mounting the first tying means with respect to the associated side of the magnetic core comprises an assembly supporting the elongated member for movement toward and away from the associated side of the magnetic core in a repeated predetermined tying cycle to bind the at least one end turn portion with cord.
 20. The apparatus of claim 19 in which the first means for tying the at least one end turn portion includes a cord feeder member attached to the support means for longitudinally swinging and turning motion to loop cord over the at least one end turn portion; motion imparting means for transmitting such motion to said cord feeder member; and motion imparting means for transmitting rectilinear and oscillatory motions to the elongated member.
 21. A method of concurrently tying cord about end turn portions of coils projecting respectively beyond each side surface of a magnetic core carrying the coils comprising the steps of: disposing one of the side surfaces of the core in a predetermined position relative to an elongated tying member having a path of travel between the one side surface and the associated end turn portion of the coils; establishing the path of travel of another elongated tying member between another side surface of the magnetic core and the associated end turn portion of the coils by sensing the location of a preselected region of the other side surface and the path of travel of the another elongated tying member; and concurrently tying cord about the end turn portions as the elongated members move along their respective paths of travel between the respective end turn portions and the associated side surface of the magnetic core.
 22. The method of claim 21 including the steps of: disposing the elongated members in their paths of travel in retracted positions free of the end turn portions, indexing the magnetic core through a predetermined angle of displacement, and once again establishing the path of travel of the another elongated tying member between the other side surface of the magnetic core and the associated end turn portion of the coils by sensing the location of another preselected region of the other side surface and the path of travel of the another elongated tying member.
 23. The method of claim 22 in which the tying cord about the end turn portions includes the step of producing a stitch pattern having a plurality of double looped stitch intervals, by forming a first loop in the intervals on one side of the end turn portions, by forming a second loop in the interval on another side of the end turn portions, pulling the first loop beneath the end turn portions to the same side as the second loop, and passing it through the second loop.
 24. A method of tying cord about at least one end turn portion of coils projecting beyond an associated side surface of a magnetic stator core carrying the coils comprising the steps of: disposing the associated side surface of the stator core in a predetermined position relative to an elongated tying member having a path of travel between the at least one end turn portion and the associated side surface; establishing a longitudinally swinging path of travel for a cord feeder member over the at least one end turn portion, sensing the location of a preselected region of the associated side surface adjacent the path of travel of the elongated tying member and controlling the paths of travel relative to the preselected region; and tying cord about the at least one end turn portion as the elongated member and the cord feeder member move along their respective paths of travel.
 25. A method of tying cord about at least one end turn portion of coils projecting beyond an associated surface at a given side of a magnetic core carrying the coils comprising the steps of: disposing the associated surface of the magnetic core in a predetermined position relative to a first tying member having a path of travel between the at least one end turn portion and the associated surface; establishing a longitudinally swinging path of travel for a second tying member over the at least one end turn portion; sensing a preselected location of the given side adjacent the path of travel of the first tying member and controlling the paths of travel relative to the preselected location; and tying cord about the at least one end turn portion as the first and second tying members move along their respective paths of travel. 